Switchable substrates for photography and video enhancement applications

Abstract

This disclosure provides systems, methods and apparatus relating to implementations of a switchable substrate that can be used in an imaging device. In one aspect, the switchable substrate includes a plurality of pixels, with each pixel having at least one switchable element. The switchable element can be switched between a first optical state and a second optical state. In the first optical state, a first spectral band of broadband light is reflected from the switchable element while a second spectral band is transmitted through the switchable element. In the second optical state, the first spectral band of the broadband light is transmitted through the switchable element while the second spectral band is reflected from the switchable element.

What is claimed is: 
     
         1 . An imaging device comprising:
 a sensor configured to detect light in visible and infrared spectral ranges propagating along an optical path from a light source; and   a switchable substrate having a forward surface that receives light from the source and a rearward surface opposite the forward surface, the switchable substrate disposed on the optical path between the source of light and the sensor, the switchable substrate including a plurality of pixels, each pixel including at least one switchable element that is capable of being switched between a first optical state and a second optical state,   wherein the switchable substrate is disposed on the optical path such that a normal to the forward surface is oriented at a non-zero angle with respect to the optical path, and such that
 when in the first optical state, a first spectral band of the light is reflected from the switchable element toward a viewing system offset from the optical path, and 
 when in the second optical state, the first spectral band is transmitted through the switchable element toward the sensor. 
   
     
     
         2 . The device of  claim 1 , wherein the non-zero angle is about 45 degrees. 
     
     
         3 . The device of  claim 1 , wherein the first spectral band includes wavelengths in a range between approximately 380 nm and 750 nm. 
     
     
         4 . The device of  claim 1 , wherein when the switchable element is in the first state, a second spectral band of the light is transmitted through the switchable element toward the sensor. 
     
     
         5 . The device of  claim 4 , wherein the second spectral band includes wavelengths in a range between approximately 750 nm and 3000 nm. 
     
     
         6 . The device of  claim 4 , wherein the second spectral band includes a portion of the near infrared spectrum. 
     
     
         7 . The device of  claim 1 , wherein the first spectral band includes a portion of the visible spectrum. 
     
     
         8 . The device of  claim 1 , wherein in the first optical state, the first spectral band is reflected with a reflectivity between approximately 60% and approximately 99%. 
     
     
         9 . The device of  claim 1 , wherein in the second optical state, the first spectral band is transmitted with a transmissivity between approximately 60% and approximately 99%. 
     
     
         10 . The device of  claim 1 , wherein the switchable element includes:
 an optical stack; and   a movable layer separated from the optical stack by a gap having a height,   wherein the movable layer is configured to be moved to change the height of the gap to switch the switchable element between the first state and the second state.   
     
     
         11 . The device of  claim 10 , wherein the optical stack includes a transparent conducting oxide. 
     
     
         12 . The device of  claim 10 , wherein the movable layer includes a transparent conducting oxide. 
     
     
         13 . The device of  claim 1 , wherein the switchable element can be switched between the first state and the second state in less than about 100 microseconds. 
     
     
         14 . The device of  claim 1 , wherein the sensor includes a photodiode including at least one of: silicon, germanium and gallium arsenide (GaAs). 
     
     
         15 . The device of  claim 1 , wherein each pixel is individually addressable to create spatial patterns in the reflected or transmitted light. 
     
     
         16 . The device of  claim 15 , wherein the at least one switchable element included in each pixel can be temporally modulated for an exposure time. 
     
     
         17 . The device of  claim 16 , wherein the at least one switchable element included in each pixel can be temporally modulated by using at least one of: time modulated signal, frequency modulated signal and pulse width modulated signal. 
     
     
         18 . The device of  claim 1 , configured as a camera. 
     
     
         19 . The device of  claim 1 , wherein the viewing system includes a display. 
     
     
         20 . An imaging device comprising:
 means for detecting light in visible and infrared spectral ranges propagating along an optical path from a source of light; and   a switchable substrate having a forward surface that receives light from the source and a rearward surface opposite the forward surface, the switchable substrate disposed on the optical path between the source of light and the detecting means, the switchable substrate including a plurality of pixels, each pixel including at least one means for switching optical states, the switching means capable of being switched between a first optical state and a second optical state,   wherein the switchable substrate is disposed on the optical path such that a normal to the forward surface is oriented at a non-zero angle with respect to the optical path, and such that
 when in the first optical state, a first spectral band of the light is reflected from the switching means toward a viewing system offset from the optical path, and 
 when in the second optical state, the first spectral band is transmitted through the switching means toward the detecting means. 
   
     
     
         21 . The device of  claim 20 , wherein the detecting means includes a photodiode including at least one of: silicon, germanium, and gallium arsenide (GaAs). 
     
     
         22 . The device of  claim 20 , wherein the switching means includes an electromechanical systems device. 
     
     
         23 . The device of  claim 22 , wherein the electromechanical systems device includes:
 an optical stack; and   a movable layer separated from the optical stack by a gap having a height,   wherein the movable layer is moved to change the height of the gap and switch the switchable element between the first state and the second state.   
     
     
         24 . A method of manufacturing an imaging device, the method comprising:
 providing a sensor configured to detect light in visible and infrared spectral ranges propagating along an optical path from a source of light; and   disposing a switchable substrate having a forward surface and a rearward surface opposite the forward surface between the source of light and the sensor such that a normal to the forward surface is oriented at a non-zero angle with respect to the optical path, the switchable substrate including a plurality of individually addressable pixels, each pixel including at least one switchable element that is capable of being switched between a first optical state and a second optical state such that
 when in the first optical state, a first spectral band of the light is reflected from the switchable element toward a viewing system offset from the optical path, and 
 when in the second optical state, the first spectral band is transmitted through the switchable element toward the sensor. 
   
     
     
         25 . The method of  claim 24 , wherein the switchable element is formed by:
 forming an optical stack over a transmissive substrate; and   forming a movable layer over the optical stack such that the movable layer is separated from the optical stack by a gap having a height.   
     
     
         26 . The method of  claim 25 , wherein the movable layer includes a transparent conducting oxide.